Spring structure



SPRING STRUCTURE Filed July 26, 1940 Patented Mar. 3Q, 1943 srarNG STRUCTURE William A. Clark and Vito Asaro, Detroit, Mich., assgnors to L. A. Young Spring and Wire Corporation, Detroit, Mich., a corporation of Michi- Application July 26, 1940, Serial No. 347,619

7 Claims.

This invention relates to improvements in spring structures.

The main objects of this invention are:

First, to provide an improved spring structure which is well adapted as a back cushion in motor vehicles where the maximum of knee room or space in front of a rear seat is required.

Second, to provide a spring structure having a plurality of bowed spring units in which the units have the desired resilience and at the same time are strongly resistant to lateral distortions or displacement.

Third, to provide a spring unit having these advantages which may be very economically produced and is easily assembled in a frame or support.

vObjects relating to details and economies of the invention will appear from the description to follow. The invention is dened in the claims.

Preferred embodiments of the invention are illustrated in the accompanying drawing, in which: v

Fig. 1 is a fragmentary plan View of a spring structure especially designed as a back spring for motor vehicle seats embodying the features of our invention.

Fig. 2 is a vertical section on line 2 2 of Fig. 1,

the pocketed coiled spring members being shown c by full lines.

Fig. 3 `is a fragmentary plan View of one of the elements or spring units of our invention.

Fig. 4 is a side elevation of the element, illusvtrating in full lines the initial or bowing set .thereof and by dotted line-s the bowed position as mounted in the frame or on supports.

Fig. 5 is an enlarged perspective view, illustrating details of the structure, particularly the attachment of the unit to the frame.

In the embodiment of our invention illustrated in the accompanying drawing, we provide a border frame l formed of heavy wire or rod stock and comprising side members 2 which are provided with oifsets 3 for locating the clips 4 and supporting them against longitudinal movement on the frame. It will be understood that the frame may be greatly varied and in practice is varied accordin g to the use to which the structure is to be put and the vehicle or other structure designed to receive the same.

We provide a plurality of bowed spring units designated generally by the numeral 5, each unit comprising a pair of wire strands 6 having longltudinally spaced loops l of substantial length, these loops being spaced to provide reaches 8, the reaches of the strands being arranged in side by vlugs l2 which are engaged side relation with the loops in opposed oppositely disposed relation.

These strands or unit members are permanently secured to each other by means of the helical'ly coiled tie members 9. These tie members are threaded or spiralled about the reaches and it will be noted that they are so arranged that coils of the tie members engage the arms of the loops. The tie members are preferably continuous as illustrated and their ends are secured to an inne-r armof the end loop by coiling or wrapping around the same, as shown at iii. The end arms H of the end loops terminate in inwardly projecting in holes I3 in the clips 4.

It will be noted that in their initial or normal state, the arms -l I are substantially spaced but when they are secured by the clips, they are collapsed to bring the lugs l2 thereof into side by side relation as shown in Fig. 5. This has the advantage of securing the arms under stress without adding to the spring resistance thereof, and minimizing a tendency for movement when the spring is undercompression.

The spring units are initially given a bowed set on an arc or curve, the radius of which is substantially less than the radius of the arc in which the spring lies when it is attached to a frame or support. Each pair of loops in eiiect constitute a spring element and allows the springs being forme-d with substantial resilience; at the same time they are very effectively resistant to lateral and distortional stresses. This is particularly desirable where they are used in structures such as shown in Figs. 1 and 2 which, as stated, is designed as a back cushion, one of the objects being to increase the space in front of a rear seat.

The upholstery springs designated generally by the numeral i6 are arranged on the spring structure described-in this case pocketed helically coiled springs of a well known type and the upholstery padding is applied and the upholstery cover I5 is suitably secured to the frame.

It will be understood that vthe upholstery padding may be applied directly to the spring -that is, the auxiliary springs It may be omitted.

While the structure is -especially desirable for motor vehicles, it has a wide range of usefulness in furniture, being adapted for both seat cushions and back cushions.

We have illustrated and described vour improvements in an embodiment which we have ioundvery satisfactory. We have not attempted to illustrate or describe other embodiments or adaptations as it is believed that this disclosure will enable those skilled in the art to embody or adapt my improvements as may be desired.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

l. In a spring structure, the combination with a border frame, of a plurality of bowed spring units disposed in spaced parallel relation relative to each other, each unit comprising two strands of spring wire having longitudinally spaced loops of substantial length disposed with the loops of the strands in opposed oppositely disposed relation, said strands having reaches between the loops arranged in side by side relation, and a continuous helical tie member coiled about the reaches of the' strands between the loops with coils thereof engaging the arms of the loops, the end coils of the tie members being secured to the end loops of the unit, the outer arms of the end loops being secured to opposite sides of the border frame with the spring units in bowed position and on an arc of substantially greater radius than the radius of the unit when it is relaxed due to its initial bowing set, the end arms' of the loops being substantially spaced when relaxed due to the initial set thereof and being secured to the frame in compressed stressed condition.

2. In a spring structure, the combination with ya border' frame, of a plurality of bowed spring units disposed in spaced parallel relation relative to each other, each unit comprising two strands of spring wire having longiutdinally spaced loops of substantial length disposed with the loops of the strands in opposed oppositely disposed relation, said strands having reaches between the loops arranged in close side by side relation, and a continuous helical tie member coiled about the reaches of the strands between the loops with coils thereof engaging the arms of the loops, the end coils of the tie members being secured to the end loops of the unit, the outer arms of the end loops `being substantially spaced in relaxed condition and being secured to opposite sides of the border frame withV the end loops stressed transverse the length of the unit and with the spring units in bowed position and on an arc of substantially greater radius thanthe radius of the unit when it is relaxed due to its initial bowing set, the loops of adjacent units being individually and resiliently resistant to torque about said reaches.

3. In a spring structure, the combination with opposed supporting members, of a plurality of bowed spring units extending between and secured at their ends to the supporting members,

said spring units each comprising strands of spring wire having longitudinally spaced oppositely disposed loops therein of substantial length extending transverse the length of the unit, and having the reaches between the loops disposed lengthwise of the unit in side by side contacting relation, and a helical tie member threaded upon said reaches with a plurality of coils thereof embracing each corresponding pair of reaches to maintain the same in said relation and prevent lateral springing of the strands under compression, said reaches being longitudinally compressed as a unit under load, the ends of the tie members being secured to the end loops of vthe unit and the end loops terminating in arms I which are secured to the supporting members under stress transverse the length of the unit,

4. In a spring structure, the combination with' opposed supporting members, of a plurality of bowed spring units extending between and secured at their ends to the supporting members, said spring units each comprising strands of spring wire having longitudinally spaced oppositely disposed loops therein of substantial length extending transverse the length of the unit, and having reaches between the loops disposed lengthwise of the unit in side by side contacting relation, the ends of said units being secured to said supporting members under stress acting transverse the length of the units, and a helical tie member `threaded upon said reaches, to maintain the same in said relation and prevent lateral Aspringing of the strands under compression, said reaches being longitudinally compressed as a unit under the load.

5. A bowed spring unit comprising two strands of spring wire having longitudinally spaced loops of substantial length disposed with the loops of the strands in opposed oppositely disposed relation, said strands having reaches between said loops arranged in closely adjacent side by side relation, and a continuous helical tie member coiled about the reaches of the strands between the loops with coils thereof engaging. the arms of the loops for resisting axial displacement thereof, the end coils of the tie members being secured to the end loops of the unit, the end arms of the loops being substantially spaced when relaxed and terminating in lugs to facilitate fattachment thereof of a supporting element, said end arms being compressed relative to one another and secured to said element in stressed condition in line with said reaches.

6. In combination with a supporting member, an elongated bowed spring unit extending transversely of said member, comprising two strands of spring wire having longitudinally spaced loops of substantial length extending transverse the length of the lunit and disposed with the loops of the strands in opposed oppositely disposed relation, said strands having reaches between said loops extending lengthwise of the unit and arranged in closelyl adjacent side by side contacting relation, said strands being secured at their ends to said frame with the end of the loops stressed transverse the length of the unit, and a continuous helical tie member coiled about the reaches of the strands between the loops with coils thereof engaging the arms of the loops for resisting axial displacement thereof. y

'7. In combination with a support, a bowed spring unit comprising strands of spring wire extending across said support having longitudinally spaced oppositely disposed loops therein of substantial length and reaches between the loops disposed in side by side contacting paralle] relation, said loops extending transverse the length of said strands and said reaches being arranged longitudinally thereof, said strands having the end loops thereof secured at their ends to said support with the end loops therein runder stress transverse the length of the unit, and a helical tie member threaded upon .said reaches with a plurality of coils surrounding each pair of adjacent reaches to prevent spreading of the strands.

WILLIAM A. CLARK.

VITO ASARO. 

